Lafourche choosing site for saltwater-control structure

Published: Tuesday, November 9, 2010 at 11:00 a.m.

Last Modified: Tuesday, November 9, 2010 at 11:17 a.m.

HOUMA — Lafourche Parish officials are debating where to place a new structure to block saltwater from creeping up Bayou Lafourche and threatening local drinking water supplies.

The structure was originally planned for Bayou Lafourche in Larose, just north of the Gulf Intracoastal Waterway. But Lafourche officials are hoping to save money and eliminate a redundant structure in Company Canal by moving the project up the bayou. A third location has been suggested near the T-Bois Bridge in Larose.

“It’s time to do it; it’s been postponed too many times,” said Lafourche Parish President Charlotte Randolph.

High salt content — caused by tides from the Gulf of Mexico pushing saltwater north into the bayou — can pose a health risk to people with high blood pressure and some other medical conditions. But coastal erosion and saltwater intrusion have made it an increasing problem in Bayou Lafourche, which supplies water to nearly 300,000 people in Lafourche, Terrebonne, Assumption and other parishes.

“It has gotten into the drinking water supply in the past through the Intracoastal and from canals to the east,” Randolph said.

The state Department of Natural Resources gave Lafourche Parish $4 million in 2007 to help design and construct a saltwater-control structure in Bayou Lafourche. The parish has a budget of $4.9 million to build the structure.

But the location of the structure has been a topic of debate, because Bayou Lafourche is a navigable waterway, and larger vessels travel the bayou’s southern reaches, said Windell Curole, director of the South Lafourche Levee District.

Saltwater-control structures work like floodgates, but instead of blocking flood waters, they’re closed temporarily when a canal or bayou is found to be carrying water with too much salinity. The structures are used throughout Terrebonne and Lafourche to help control saltwater intrusion from the Gulf of Mexico and keep it from destroying interior freshwater swamps and marshes.

The first site proposed for the structure would be located in Larose on Bayou Lafourche just above the Gulf Intracoastal Waterway, but that project has run into land-rights issues, officials said. So now the parish government is debating whether to move the structure upstream, possibly eliminating an older saltwater control structure on Company Canal.

The structure could be built in Bayou Lafourche just south of the Mathews water plant, blocking any saltwater creeping up toward drinking water collection sites from the Gulf Intracoastal Waterway, Bayou Lafourche and Company Canal. The Company Canal Saltwater Control Structure could also be dismantled, and the barge used as a base could be repurposed to build the new structure in Bayou Lafourche, Randolph said.

The Company Canal saltwater-control structure was built in 2003 for $1.6 million but has only been closed five times to prevent salt water from reaching Lafourche Parish Water District No. 1, which draws water from Bayou Lafourche near Lockport. Most of those closures lasted for a week or more between October 2005 and January 2007. Archie Chiasson, manager of the Bayou Lafourche Freshwater District, said he begins watching the salt levels in the canal between September and January, when there may be weeks or months with little rainfall and when cold-front winds start blowing Gulf water up the canal.

At a public meeting last week discussing the control structure’s location, it was suggested it could also be built in Bayou Lafourche immediately north or south of the T-Bois bridge in Larose. Randolph said that location will also be considered.

Randolph said the structure wouldn’t cause many problems for navigation because it could remain open most of the year.

Lafourche Parish spokesman Brennan Matherne said a second public meeting will be held to discuss the saltwater control structure’s location, but a date hasn’t been picked yet.

Staff Writer Nikki Buskey can be reached at 857-2205 or nicole.buskey@houmatoday.com.

<p>HOUMA — Lafourche Parish officials are debating where to place a new structure to block saltwater from creeping up Bayou Lafourche and threatening local drinking water supplies.</p><p>The structure was originally planned for Bayou Lafourche in Larose, just north of the Gulf Intracoastal Waterway. But Lafourche officials are hoping to save money and eliminate a redundant structure in Company Canal by moving the project up the bayou. A third location has been suggested near the T-Bois Bridge in Larose.</p><p>“It's time to do it; it's been postponed too many times,” said Lafourche Parish President Charlotte Randolph.</p><p>High salt content — caused by tides from the Gulf of Mexico pushing saltwater north into the bayou — can pose a health risk to people with high blood pressure and some other medical conditions. But coastal erosion and saltwater intrusion have made it an increasing problem in Bayou Lafourche, which supplies water to nearly 300,000 people in Lafourche, Terrebonne, Assumption and other parishes.</p><p>“It has gotten into the drinking water supply in the past through the Intracoastal and from canals to the east,” Randolph said.</p><p>The state Department of Natural Resources gave Lafourche Parish $4 million in 2007 to help design and construct a saltwater-control structure in Bayou Lafourche. The parish has a budget of $4.9 million to build the structure.</p><p>But the location of the structure has been a topic of debate, because Bayou Lafourche is a navigable waterway, and larger vessels travel the bayou's southern reaches, said Windell Curole, director of the South Lafourche Levee District.</p><p>Saltwater-control structures work like floodgates, but instead of blocking flood waters, they're closed temporarily when a canal or bayou is found to be carrying water with too much salinity. The structures are used throughout Terrebonne and Lafourche to help control saltwater intrusion from the Gulf of Mexico and keep it from destroying interior freshwater swamps and marshes.</p><p>The first site proposed for the structure would be located in Larose on Bayou Lafourche just above the Gulf Intracoastal Waterway, but that project has run into land-rights issues, officials said. So now the parish government is debating whether to move the structure upstream, possibly eliminating an older saltwater control structure on Company Canal.</p><p>The structure could be built in Bayou Lafourche just south of the Mathews water plant, blocking any saltwater creeping up toward drinking water collection sites from the Gulf Intracoastal Waterway, Bayou Lafourche and Company Canal. The Company Canal Saltwater Control Structure could also be dismantled, and the barge used as a base could be repurposed to build the new structure in Bayou Lafourche, Randolph said. </p><p>The Company Canal saltwater-control structure was built in 2003 for $1.6 million but has only been closed five times to prevent salt water from reaching Lafourche Parish Water District No. 1, which draws water from Bayou Lafourche near Lockport. Most of those closures lasted for a week or more between October 2005 and January 2007. Archie Chiasson, manager of the Bayou Lafourche Freshwater District, said he begins watching the salt levels in the canal between September and January, when there may be weeks or months with little rainfall and when cold-front winds start blowing Gulf water up the canal.</p><p>At a public meeting last week discussing the control structure's location, it was suggested it could also be built in Bayou Lafourche immediately north or south of the T-Bois bridge in Larose. Randolph said that location will also be considered.</p><p>Randolph said the structure wouldn't cause many problems for navigation because it could remain open most of the year. </p><p>Lafourche Parish spokesman Brennan Matherne said a second public meeting will be held to discuss the saltwater control structure's location, but a date hasn't been picked yet.</p><p>Staff Writer Nikki Buskey can be reached at 857-2205 or nicole.buskey@houmatoday.com.</p>